grid computing - Multiple Masters in GridGain

A few years ago, this gridgain question was posed and addressed at Gridgain failover of master (sender) nodeFast forward to today. We run gridgain 6.2.1 (open source edition) and are trying to enforce high availability of our gridgain master (in case the hardware or the master process fails). From a high level perspective, we submit (distributable) jobs to the master node via a continuous mapper manager that we define. As per the previous accepted answer to the question, this was not possible in 2011 . Has the status quo changed in 2015, or are...Read more

GridGain multicast discover does not find cluster nodes

I'm trying to setup a gridgain cluster in a cloud environment ('ve verified that UDP multicast is available and port 47400 is open in this environment, but unfortunately GridGain is unable to find the other nodes when they are launched. Do you have clue why it is not working. Following you can find below the a cluster node log: INFO o.g.grid.kernal.GridKernal%nextflow - Config URL: n/aINFO o.g.grid.kernal.GridKernal%nextflow - Daemon mode: offINFO o.g.grid.kernal.GridKernal%nextflow - OS: Linux 2.6.32-358.2.1.el6.x...Read more

GridGain transactions issues

In our project we are testing how transactions work in distributed environment. As a part of the project we are testing opensource edition of GridGain 6.5.5.We have faced lots of problems in the following testcase:We are testing a cache without any additional rules.The cache stores an id-String as a key and BigDecimal as a value.We are testing base operations (addition and subtraction) on values of the first cache from 6, 12 and 18 clients. One operation looks like "subtract X from A, add X to B".GridGain application is deployed as a .war file ...Read more

grid computing - Gridgain elastic scaling - can't get work stealing to behave as I want

I hope someone has done this before, or if someone can advise whether or not Gridgain supports this functionality.My use case is:Start a Gridgain node using examples/config/example-compute.xml modified to support work stealing (see below)Submit 300 tasks to the cluster.They start executing on the first node, but as they take time to execute, there is a long queue of outstanding tasksStart a new node using same configuration and watch it join the clusterShouldn't node 2 steal some of the work from the first node? It does not unfortunately and we...Read more

gridgain - Performance analysis of Apache ignite

How can we analyze performance of Apache ignite. Task analysis in only shows duration of task, its executions(whether its finished or not). Whereas Node analysis only shows snapshot of particular time instant for cpu, memory usage etc. I want to get cpu, disk, memory utilization of certain task over its time period. So how can I get that?...Read more

gridgain - Cache Metrics not getting updated in Apache Ignite

I have written following code for simple in-memory cache put operation. Using cache metrics I am trying to get number of cache puts at current time instant. But always I am getting 0 as number of cache puts. Am I missing some configuration settings? import;import org.apache.ignite.Ignite;import org.apache.ignite.IgniteCache;import org.apache.ignite.IgniteException;import org.apache.ignite.Ignition;import org.apache.ignite.cache.CacheMetrics;import org.apache.ignite.cache.query.annotations.QuerySqlField;import org.apache.i...Read more

gridgain - Distributed SQL query performance in Apache Ignite

I have defined following 2 classes Person(with PersonKey) and Company() with companyId as key. PersonKey is affinity collocated with companyId. Now I am trying to do SQL distributed join (Person.companyId = Company.companyId) on 2 nodes connected in grid. I repeated same join with only single node. With distributed join in 2 nodes I should get 2x performance improvement, but it is performing worst with comparison to single node. Why is this happening? Are both nodes not participating in computation(here select query) part?class PersonKey { /...Read more

gridgain - Apache Ignite - data rebalancing doesn't work properly

I have a cluster of 2 nodes (A & B).I put 2 data elements in cache from Node A (e.g. I put firstName and lastName in cache).Now I am reading those data elements from cache on Node B. Node B is able to read both of elements from cache successfully.Now we shut down Node A. Node B isn't able to read one of data object from cache. I have added a fully working application to reproduce the issue. I have also added file in code with exact steps to reproduce the issue. am maki...Read more

gridgain - Connection Error in Ignite web agent

For analysis of node in Apache ignite, I am using monitoring tool at [1] : I tried running for making connection with web server at link above, but I am getting following error messege. I also tried replacing localhost with IP address of machine, but still it is not working. While running ignite node do I have to start ignite REST server for connection? If yes then how can I enable this REST server mode through java code? ignite-web-agent-1.7.2]$ . Java HotSpot(TM) 64-Bi...Read more

gridgain - Error while connecting 2 nodes in grid in Apache Ignite

I am getting following error while connecting 2 nodes in grid in Apache Ignite. These 2 nodes detect themselves when I run script on both nodes. But when I try to start ignite on one node using and on another node using java code, I am getting following error. [17:23:44] __________ ________________ [17:23:44] / _/ ___/ |/ / _/_ __/ __/ [17:23:44] _/ // (7 7 // / / / / _/ [17:23:44] /___/\___/_/|_/___/ /_/ /___/ [17:23:44] [17:23:44] ver. 1.7.0#20160801-sha1:383273e3[17:23:44] 2016 Copyright(C) Apache Soft...Read more

Cache Queues And Load Balancing in GridGain

In the docs (, it is mentioned that jobs on a cache queue can be consumed by worker grids offering an alternative means of load balancing .I investigated this concept thus:Implemented a producer that enqueues GridRunnable jobs on a partitioned cache (distributed blocking queue). I had to use a partitioned queue (since the local queue, by definition, isn't suited to multi-grid access).Implemented a consumer that , on startup, spawned n listener threads that perpetually block upon...Read more

Gridgain leader election pattern

What is the advised approach to ensuring a particular process is running exactly once within the grid?Usecase would be subscription of a single multiplexed stream from a remote source in order to update data across the grid. We need to elect the node to subscribe and elect a new node to subscribe when that node fails.Is there any pre-built pattern for this in gridgain or is it solved by a combination of listening to grid lifecycle events and a distributed CAS operation?Another usecase would be a singleton job that must run forever, migrating to...Read more